Act

Annabeth could tell that her explanation did not, by any chance, make it easier for her sisters to understand why the entire room was quiet after she performed. 

"Um... to begin with, I didn't perform the piece given to me by mother," Annabeth began. 

Her sisters gasped, their eyes widening in surprise and concern. One reason for that would be the fact that no one in their family ever went against directions given at official events, especially one of this much effect on their life after they leave the palace. Second, was the huge question of what she performed in place of it.